Difference Between Virus and Worm

Computer virus and computer worm are two types of malware. These programs are sometimes designed for simply amusement while some are designed to create harmful effects.

Computer Virus

Computer viruses are malicious software, often executable files that have the ability to replicate and transfer itself from one computer to another through file transfer devices. They can attach themselves to another executable file and transfer through that too. Viruses are classified into two types as resident and non-resident viruses.

Nonresident viruses are designed to distribute themselves by attaching themselves to an executable file. There are two components in the nonresident viruses that operate as follows; the finder module looks for executable files within the system, then the replicator module copies and attaches the copies to the found executable files. Therefore, when the original exec file is running, virus also starts to run in the back ground.0 Resident virus works differently to the nonresident viruses, where the finder module is absent. Whenever an executable file is running in the computer, it becomes a target for the replicator module and a copy is attached to the executable file; this effectively infects a majority of the exec files.

A virus affecting a computer may reduce the memory or disk space, wipe the hard drives, modify the data in the files, or simply damage the files. The antivirus programs can counter these actions and protect the computer.

Computer Worm

Computer worms are malware designed to spread through the internet and other networks. They can spread through simple file transfer/download or through email. Worms can affect the computer network by consuming bandwidth and the computer system by flooding the memory with replicates of the program. Unlike viruses, worms do not need a host file for execution. They operate independently within the computer system.

There are different types of worms. Email worms, instant messaging worms, internet worms, IRC worms, and file-sharing networks worms are the common types of worms. Worms exploit the holes in the firewall and antivirus system.

What is the difference between Computer Virus and Worm?

• Computer viruses are executable files or files that require an executable file to be attached to operate. Worms are independent files where the file exists on its own within the memory.

• Computer viruses replicate themselves, and get attached to executable files for operation but stays within the computer unless the files are transferred. Worms replicate and transfer themselves through the networks.

• Computer worms can be remotely controlled while the viruses are independent.

• The viruses infect the files in the computer while worms consume the resources excessively such as the bandwidth and make the system slow and unstable by replicating and running the programs in memory.